Regional vulnerability analysis of Catalan beaches to storms

Abstract

A framework to estimate coastal vulnerability to storm impacts at a regional scale is presented. It assesses the physical coastal vulnerability to storm impacts by separately estimating two components: flooding and erosion. It covers the following steps: (i)characterization of the forcing, (ii) evaluation of the induced beach response – inundation and erosion – (hazards quantification), (iii) coastal zone characterization, (iv) definition of a coastal vulnerability index to storms – a composite of two partial vulnerability estimations, the flood vulnerability and the erosion vulnerability indices-, and (v) assessment of the coastal vulnerability. Instead of assessing the vulnerability associated with a given storm, the forcing is defined in terms of representative storms which are obtained by classifying storms in the area using a 5-class system similar to that used for hurricanes (weak, moderate, significant, severe and extreme). Later, a vulnerability assessment for the entire coast to each storm category is produced. The method has been derived for and applied to the Catalan coast (NW Mediterranean) but can be easily adapted to other coasts. It permits managers to identify 3 coastal stretches sensitive to a given storm class for a given induced hazard (flooding, erosion or combination of both) to decide where to take actions.